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1.
J Org Chem ; 88(13): 9381-9387, 2023 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-37184952

RESUMEN

A 14-membered cyclic compound (3) containing amide, amino, and carbamate groups, which was serendipitously obtained in the oily residue after the separation of 4-benzyl-1,4,7,10-tetraazacyldododecane-2,6-dione (2a) and 4,16-dibenzyl-1,4,7,10,13,16,19,22-octaazacyclo-tetracosane-2,6,14,18-tetraone (2b), is reported. The structure of 3 is formally a CO2 insertion between positions 3 and 4 of the 12-membered ring in 2a. The CO2 insertion was confirmed in the synthesis of diethyl 2,2'-(benzylazanediyl)diacetate (1) by the reaction of benzylamine with ethyl bromoacetate using K2CO3 as the base. In addition, the selective synthesis of 3 and ethyl N-benzyl-N-((2-ethoxy-2-oxoethoxy)carbonyl)glycinate (5) and their kinetic behavior are reported. The reaction of 5 with triethylenetetramine afforded a 17-membered macrocycle (7), which was obtained in an 18% yield. Compounds 6 and 8 were prepared from 3 and 7 by introducing benzyl groups to improve their solubility in organic solvents. Titration experiments using 1H NMR showed that both 6 and 8 exhibit Li+ selectivity.


Asunto(s)
Amidas , Carbamatos , Dióxido de Carbono , Espectroscopía de Resonancia Magnética , Esqueleto
2.
Inorg Chem ; 62(31): 12272-12282, 2023 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-37480022

RESUMEN

Four types of bis- and tris(tetra-armed cyclen)s were prepared. 2MF is a bis(tetra-armed cyclen) with electron-rich side arms (three 4-methoxybenzyl groups) and electron-deficient side arms (three 3,5-difluorobenzyl groups), connected by a 4,4'-dimethyl-1,1'-biphenyl moiety. 3MFM is a tris(tetra-armed cyclen) with 4-methoxybenzyl and 3,5-difluorobenzyl groups introduced on both ends and the central cyclen, respectively. 4MFM is a V-shaped analogue of 3MFM. 3FMF is a tris(tetra-armed cyclen) where the aromatic side arms at both ends and the central cyclen of 3MFM are exchanged. The regioselective coordination of silver(I) ions by these ligands is reported. Initially, we added Ag+ ions to a compound (2MF) that consists of tetra-armed cyclen with 4-methoxybenzyl groups as an electron-donating substituent on the aromatic rings and 3,5-difluorobenzyl groups as an electron-withdrawing substituent. 1H NMR and 19F{1H} NMR spectroscopy exhibited that the cyclen with the 4-methoxybenzyl groups formed a complex with Ag+ ions first, followed by the cyclen with the 3,5-difluorobenzyl groups. Next, we employed a compound (3MFM) with three cyclen units, where the cyclen at each end was functionalized with three 4-methoxybenzyl groups, and the central cyclen was functionalized with two 3,5-difluorobenzyl groups. Upon adding Ag+ ions, we observed that the cyclen units at both ends formed complexes with Ag+ ions initially, followed by the central cyclen forming a complex with Ag+ ions. When we used 4MFM, which is a V-shaped compound, the Ag+-induced-1H NMR chemical shift changes are almost the same results as the 3MFM. Furthermore, we synthesized a compound (3FMF) by interchanging the substituents on the cyclen units at the ends and the center. Interestingly, the order of the complex formation was reversed in this compound. These results demonstrated that tuning the electron density on the aromatic side arms through substituents makes it possible to achieve regioselective coordination with Ag+ ions in bis- or tris(tetra-armed cyclen)s.

3.
J Org Chem ; 87(18): 12434-12440, 2022 09 16.
Artículo en Inglés | MEDLINE | ID: mdl-36026614

RESUMEN

A flexible cylindrical cryptand (1b) with two m-phenylene-26-crown-8 ethers has been prepared, and its complexing properties with respect to tetravalent cationic bis-paraquat guests have been investigated. Diffusion-ordered spectroscopy nuclear magnetic resonance (NMR) and titration experiments using cold electrospray ionization mass spectrometry and 1H NMR revealed that 1b has versatile complexing properties with respect to tetravalent cationic guests used despite the guest molecules' length and shape.


Asunto(s)
Éteres Corona , Paraquat , Éteres Corona/química , Ligandos , Espectroscopía de Resonancia Magnética , Conformación Molecular , Paraquat/química
4.
J Org Chem ; 86(14): 9847-9853, 2021 07 16.
Artículo en Inglés | MEDLINE | ID: mdl-34098715

RESUMEN

The synthesis of an octa-armed 24-membered cyclic octaamine (1) is reported. When 4-benzyl-1,4,7,10-tetraazacyclododecane-2,6-dione (3a) was prepared by the reaction of diethylenetriamine with diethyl N-benzyliminodiacetate (2), a dimeric macrocycle (3b) was obtained as a byproduct in a 5% yield. An octa-armed 24-membered cyclic octaamine (1), named Cosmosen, was prepared via the reductive amination and reduction of 3b. The binding constants for the 1:1 and 2:1 (Ag+/1) complexation of 1 were estimated to be ca. 7.9 and 13.9, respectively, by titration experiments using UV-vis spectrometry in methanol and chloroform (v/v, 9:1) solutions at 298 K.


Asunto(s)
Aminación
5.
Inorg Chem ; 60(15): 11320-11327, 2021 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-34253012

RESUMEN

Argentivorous molecules with mono, di, tri, tetra, and penta-oxyethylene chains in aromatic side-arms were prepared (L1-L5). Titration experiments using proton nuclear magnetic resonance and cold electrospray ionization (cold-spray ionization, CSI) mass spectrometry showed that silver ions were trapped in the cyclen moiety and the arranged oxyethylene chains of the side-arms when two equivalents of silver ions were added. The silver complexes formed by adding one equivalent of silver ion to L2-L5 bind alkali metal ions using the oxyethylene chains; alkali metal ion-induced CSI mass spectral changes of L2-L5 were measured in the absence and presence of silver ions to compare the binding properties of the ligand for Li+, Na+, and K+ ions. As a result, the intensity ratios of [L + H + M]2+/[L + H]+ in L1-L3 were almost zero or very low. L4 and L5, which have tetra(oxyethylene) and penta(oxyethylene) chains, respectively, bind a larger size of alkali metal ions. On the other hand, in the presence of silver ions, the ratio for [L + Ag + M]2+/[L + H]+ (M = Li, Na, K) in L2-L5 was increased. The highest [L + Ag + M]2+/[L + H]+ ratios for K+ were observed in L4 and L5, while selectivity for Na+ was observed in the case of L2 and L3. These results indicate that the increased binding ability and selectivity by L2-L5 are due to the arrangement of oxyethylene chains by the conformational change of the aromatic side-arms. The Ag+-induced carbon-13 nuclear magnetic resonance spectral changes suggested that the second and third oxyethylene units, close to the benzene, are involved in the coordination of the second metal ion.

6.
Inorg Chem ; 60(12): 9141-9147, 2021 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-34085518

RESUMEN

The synthesis of argentivorous molecules (L1 and L2) having two chromophores (4-(anthracen-9-yl)benzyl or 4-(pyren-1-yl)benzyl groups) and two benzyl groups and the fluorescence properties of their silver complexes in a solution and the solid state are reported. A crystallographic approach for the Ag+ complexes with L1 and L2 revealed that the observed fluorescence changes stem from the excimer formation and extinction of fluorescent. Furthermore, binding stabilities of L1 and L2 toward Ag+ ions were estimated by the Ag+-induced UV-vis and PL spectral changes.

7.
Inorg Chem ; 60(3): 1738-1745, 2021 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-33444007

RESUMEN

A tetra-armed cyclen (L) with two substituted 3,5-difluorobenzyl and two substituted pyridine-4-yl methyl groups at the 1,4- and 7,10-positions of the cyclen ring as side arms was synthesized. When L was reacted with 1 equiv of the silver(I), dimetallo[3.3]paracyclophane-like 2:2 cyclic dimer, [Ag2(L)2](PF6)2, was obtained. The reaction of L with 2 equiv of silver(I) gave a 3:6 cyclic trimer, [Ag6(L)3(CH3CN)3](OTf)6·3CH3CN. Furthermore, reversible complexation between the 2:2 cyclic dimer and 3:6 cyclic trimer was confirmed by 1H NMR and the CSI mass in the addition of silver(I) or the [2.2.2]cryptand.

8.
Inorg Chem ; 60(20): 15159-15168, 2021 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-34587442

RESUMEN

Bis-argentivorous molecules (La and Lb), which have phenyl and 4,4'-biphenyl groups as linkers, have been prepared. The structures of Ag+ complexes with the new ligands (La and Lb) were investigated in solution and the solid state. The CSI-MS and 1H NMR titration of La and Lb with Ag+ show 1:1 and 1:2 complexes depending on the [Ag+]:[L] ratios. In the solid-state structures, single crystals of La and Lb with 2 equiv of Ag+ were prepared. X-ray crystallography of the silver(I) complexes with La and Lb showed that an intramolecular racemic structure (Δ(δδδδ)Λ(λλλλ) form) and a racemic mixture of Δ(δδδδ)Δ(δδδδ) and Λ(λλλλ)Λ(λλλλ) forms were formed, respectively. The dynamic 1H NMR studies suggest the following: (i) the activation entropies (ΔS⧧) of the side arm rotations in the Ag+ complex with La were all negative, indicating restricted rotation of the side arms due to their shortness, and (ii) the ΔS⧧ values of the Ag+ complexes with Lb were negative only when the side arms of both cyclens rotated simultaneously, and the ΔS⧧ values for the 1:1 and 1:2 complexes were positive when one cyclen side arm was rotated. These values of ΔS⧧ indicate that the biphenyl side arms between the two cyclens are not long enough to rotate the ring freely.

9.
Angew Chem Int Ed Engl ; 60(2): 650-654, 2021 01 11.
Artículo en Inglés | MEDLINE | ID: mdl-32959445

RESUMEN

Tetra-armed cyclen (1) bearing two 4-(4'-pyridyl)benzyl and two 3,5-difluorobenzyl groups and its Ag+ complexes were prepared and structurally characterized. The complexes formed between 1 and Ag+ undergoes a reversible structural transformation between a 2:2 dimeric complex and a 3:5 pentacyclic trefoil complex with changes in the Ag+ /1 molar ratio. It was also revealed that the 3:5 trefoil complex could encapsulate benzene and [D6 ]benzene selectively in solid-state. The benzene-included structures are stabilized by C-H⋅⋅⋅F-C interactions between the benzene molecule and the ligand molecule.

10.
Analyst ; 145(5): 1667-1676, 2020 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-31967119

RESUMEN

To obtain a mechanistic understanding of the effects derived from fluorophores, solvents and anions on heavy metal sensing, two NOS2-macrocycle-based fluorosensors with different fluorophores (L1: 9-methylanthracene, L2: benzothiazolyl) were synthesised. In this regard, particular attention was given to monitoring the cation-ligand, cation-anion and cation-solvent interactions from the detailed complexation processes in both the solution and solid states while considering the structure-function relationship. L1 showed turn-on type silver(i) selectivity over other metal ions, including mercury(ii), in ethanol. According to the complexation results obtained by titration (UV-vis, fluorescence and NMR), cold-spray ionization mass spectrometry and X-ray crystallography, the observed silver(i) sensing by L1 is mainly due to its 1 : 1 complexation with silver(i) via the Ag-Ntert bond and the strong solvation of mercury(ii). Thus, the turn-on sensing for silver(i) can be explained by the CHEF effect, in which the coordination of silver(i) to the receptor unit effectively prevents PET quenching. As a dual-probe (UV-vis and fluorescence) chemosensor, L2 showed fluorescence turn-off type selectivity for both silver(i) and mercury(ii) in ethanol. In acetonitrile, L2 showed improved fluorescence turn-off type selectivity for mercury(ii) with ClO4- and NO3-; however, no such responses were observed with other anions, such as Cl-, Br-, I-, SCN-, OAc- and SO42-. Together with the complexation results by titration, the crystal structures of an endocyclic mercury(ii) perchlorate complex and an exocyclic mercury(ii) iodide complex revealed that the anion-controlled mercury(ii) sensing by L2 arises from the endo- and exo-coordination modes depending on the anion coordinating ability, which induces either metal-receptor/fluorophore binding (Hg-Ntert and Hg-Nfl) or no binding. Taken collectively, the photophysical, thermodynamic and structural results of the complexations herein suggest that the sensing properties of heavy metal ions by macrocycle-based fluorosensors are very sensitive not only to the cation-receptor and cation-fluorophore interactions but also to the cation-anion (endo/exo-coordination modes) and/or cation-solvent interactions.

11.
Inorg Chem ; 59(15): 11166-11173, 2020 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-32678583

RESUMEN

The synthesis of a tetra-armed cyclen (L) with two benzyl groups at the 1- and 7-positions and two pyridin-4-ylmethyl groups at the 4- and 10-positions as side arms and the solvent- and/or molar-ratio-dependent coordination modes in the formation of silver(I) complexes are reported. 1H NMR and cold-spray-ionization mass spectrometry studies suggest that a silver(I) complex with L gives different species depending on the molar ratio of silver ions used as the reactant. Furthermore, the conformation of cyclen in the one-dimensional (1D) coordination polymers, obtained using 2 equiv of silver(I), changes depending on the presence or absence of acetonitrile. When L was reacted with 1 and 2 equiv of silver(I) triflate in a mixed solvent system (CH2Cl2/CH3OH/CH3CN), a dimetallo[3.3]paracyclophane-like discrete cyclic dimer, [Ag2L2](OTf)2 (1), and a 1D coordination polymer, [Ag2L(OTf)2(CH3CN)]n (2), respectively, were obtained as single crystals. In the absence of acetonitrile, a zigzag 1D coordination polymer, {[Ag2L(OTf)]OTf·3CH2Cl2}n (3), was obtained when 2 equiv of silver(I) was used. Molar-ratio-dependent structural changes were not observed when L was reacted with AgBF4 or AgPF6 in the CH2Cl2/CH3OH/CH3CN mixed-solvent system. The solvent effect on the coordination modes can be explained by the coordination ability of the solvents toward the metal cation affecting the conformation of the cyclen.

12.
Inorg Chem ; 59(18): 13435-13441, 2020 Sep 21.
Artículo en Inglés | MEDLINE | ID: mdl-32857508

RESUMEN

We report the synthesis of chiral tetra-armed cyclens, having an asymmetric center at one side-arm, that show selective chiral enhancement with silver(I). When the chiral ligand forms a silver(I) complex, the side-arms cover the silver(I) incorporated into the cyclen. The asymmetric center controls the conformation of the side-arms in one direction, increasing the molar ellipticity of the CD spectrum. Chiral cyclens substituted with biphenyl groups exhibit large molar ellipticity values with strong exciton coupling effects.

13.
Inorg Chem ; 59(24): 18444-18451, 2020 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-33301678

RESUMEN

The proton signals at the 2'- and 6'-positions of the aromatic side arms of a silver(I) complex with a chiral tetra-armed cyclen ((S)-L2) are assigned by comparison with 1H NMR spectra and X-ray structure of Ag+ complexes with three analogues of (S)-L2: (S)-L23D having one benzyl group and three deuterium-substituted benzyl groups, (S)-L22D having two benzyl groups and two deuterium-substituted benzyl groups, and (S)-L2F having three benzyl groups and one 4'-fluorobenzyl group. An interaction factor is defined by using the X-ray structures. The chemical shift values of the proton signals in the aromatic side arms can be explained by using the interaction factors that are defined by the dihedral angles, the angles between two mean planes, and the CH···π distances from the X-ray data of the (S)-L2/Ag+ complex.

14.
Chemistry ; 25(4): 949-953, 2019 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-30450626

RESUMEN

Some biological receptors change their shapes and rigidity by metalation to recognize substrates precisely via adaptive guest binding process. Herein we present a semi-flexible tricyclic host molecule whose conformation is rigidified by dimetalation to uptake organic guests selectively. Considering two metal binding sites and an empty space between them, pillar[5]-bis-thiacrown (L) was synthesized. The tricyclic host L forms a disilver(I) complex [Ag2 L(NO3 )2 ], with an Ag⋅⋅⋅Ag separation of 9.976 Å. Binding studies based on 1 H NMR including 2D NOESY and DOSY experiments towards α,ω-dicyanoalkanes [CN(CH2 )n CN, n=2-6, shortly C2-C6] demonstrated that the dimetalated L, Ag2 L preferentially recognizes C2 over other guests than that of free L. Furthermore, the dimetalated the host only uptakes C2 in the presence of other guests. Crystal structures support the idea that the space between two silver(I) centers plays a decisive role on the selective guest binding forming an Ag-C2-Ag@L arrangement via the length-selective recognition. This work demonstrates the chemical example of the adaptive guest binding and presents a new perspective on the metallosupramolecules of pillararenes.

15.
Inorg Chem ; 58(2): 1177-1183, 2019 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-30596239

RESUMEN

Formation of a copper(I) iodide cluster based luminescent metal-organic frameworks (LMOFs) and its utilization for the detection of cysteine (Cys) in aqueous solution are reported. The reaction of bis(amidoquinoline) ligand (L) with copper(I) iodide afforded an LMOF {[(Cu2I2)L2]·2DMSO} n (1) with a 44-sql topology linked by Cu2I2 clusters as a thermodynamic product. Time- and temperature-dependent PXRD experiments confirmed that the entire formation process for 1 is kinetically and thermodynamically controlled. Interestingly, LMOF 1 was also obtained under the mechanochemical condition. Moreover, LMOF 1 dispersed in water shows a selective quenching for Cys over other amino acids due to the strong affinity of Cys to copper(I) iodide. On the basis of the NMR data of L isolated from the decomposition of 1, the decomposition-displacement mechanism was proposed for the sensing of Cys. This result might be utilized for the practical detection of Cys because the sensing material can be prepared simply, and the sensing process is performed in aqueous media.

16.
Angew Chem Int Ed Engl ; 58(33): 11296-11300, 2019 Aug 12.
Artículo en Inglés | MEDLINE | ID: mdl-31209942

RESUMEN

A one-pot reaction of the A1/A2-thiopyridyl pillar[5]arene L with silver(I) trifluoroacetate in the presence of the linear dinitrile guest C8, [CN(CH2 )n CN, n=8], afforded the first example of a two-dimensional (2D) poly-pseudo-rotaxane {[(µ4 -Ag)2 (C8@L)2 (µ-C8)](CF3 CO2 )2 }n . Surprisingly, in this structure the C8 guest not only threads into the pillar[5]arene unit but also crosslinks the 1D coordinative polymeric arrays. The formation of the 2D poly-pseudo-rotaxane is driven by an adaptive rearrangement of the components that minimizes the steric clashes not only between the threaded guests but also between the threaded and crosslinked guests where crosslinking occurs. A pathway for the formation of the 2D poly-pseudo-rotaxane is proposed.

17.
J Am Chem Soc ; 140(30): 9669-9677, 2018 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-29975523

RESUMEN

Chiral inversion of single molecules has been a challenging task because chirality information controls structures and functions of various molecules, artificial nanostructures, DNA, and proteins. Herein we present a pseudo[1]catenane-type molecule whose planar chiral inversion is driven by a metal ion under the control of anions for the first time. Considering an in-out equilibrium of a fused thiacrown and the soft metal binding, pillar[5]thiacrown ( rac-L) was synthesized. Two planar-chiral enantiomers of rac-L ( in-pS-L and in-pR-L) were isolated and the absolute configuration was determined by circular dichroism and single crystal X-ray analysis. The in-pS-L recognizes Hg2+ to trigger the chiral inversion to out-pR-L, to our surprise; it takes place only in the presence of ClO4- or NO3- among the anions used. In the mercury(II) perchlorate complex solution, anion-exchange from ClO4- to I- or removal of Hg2+ by addition of S2- makes the system reversible. The crystallographic approach reveals that the anions act as coordination mode-directing species ( endo- or exo-coordination) which play a decisive role on the chiral inversion. For instance, the week coordinating ClO4- allows Hg2+ to locate inside the thiacrown ( endo-coordination) which causes the chiral inversion from in-pS-L to out-pR-L due to the expansion of the thiacrown unit upon endo-mode complexation. Oppositely, the strong coordinating I- takes Hg2+ out of the thiacrown ( exo-coordination) without large conformational changes of the thiacrown, resulting in no chiral inversion. A series of experimental works was also accomplished with the other enantiomer in-pR-L, which afforded identical results. Consequently, the chiral inversion is governed by steric factors that arise from the coordination modes depending on the coordinating ability of anions. This work demonstrates the first chiral inversion induced by combination of metal ion and anion and presents a new perspective on the supramolecular coordination chemistry of pillar[ n]arenes.

18.
J Org Chem ; 83(8): 4800-4804, 2018 04 20.
Artículo en Inglés | MEDLINE | ID: mdl-29565126

RESUMEN

Determination of a thermal E/ Z isomerization barrier of first generation molecular motors is reported. Stable ( E)-1a directly converts to stable ( Z)-1c without photochemical E/ Z isomerization. The activation Gibbs energy of the isomerization was determined to be 123 kJ mol-1 by circular dichroism spectral changes. Density functional theory calculations show that ( Z)-1c is ∼11.4 kJ mol-1 more stable than ( E)-1a.

19.
Inorg Chem ; 57(11): 6289-6299, 2018 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-29722969

RESUMEN

A 20-membered N2O2S2-macrocycle (L1) and a 40-membered N4O4S4-macrocycle (L2) were employed as a [1:1] and a [2:2] cyclization product, respectively, for the preparation of diverse types of supramolecular complexes including a cascade complex. Six complexes (1-6) of the smaller macrocycle L1 including discrete to continuous forms, mono- to heteronuclear, and endo- to exo- and endo/exocoordination were prepared and their coordination modes were discussed systemically. First, the reaction of L1 with CuI in the presence of trifluoroacetic acid afforded an exocyclic 1-D coordination polymer {[(µ4-Cu4I4)(HL1)2](CF3COO)2} n (1). Meanwhile, the reaction of L1 with Cu(ClO4)2·6H2O afforded a typical endocyclic mononuclear complex [CuII(L1)](ClO4)2·H2O (2). In the reactions of L1 with CdX2 (X = Br and I), isostructural sandwich-type complexes [Cd(L1)2Br2] (3) and [Cd(L1)2I2] (4) were isolated. The treatment of L1 with Hg(ClO4)2 also afforded a sandwich-type complex [Hg(L1)2](ClO4)2 (5). One-pot reaction of L1 with a mixture of HgI2 and CdI2 afforded a dumbbell-type heteronuclear complex {[Cd(L1)]2(µ-Hg2I6)}[Hg2I6] (6), in which the Cd(II) ion occupies the macrocyclic cavity. Further, such two endocyclic Cd(II) complex units are bridged by a square-type (µ-Hg2I6)2- cluster remaining another same cluster separately. The comparative NMR data exhibited a higher affinity of Cd(II) over Hg(II) toward L1, in the parallel to the situation occurred in the solid state. Meanwhile, complexations of the extra-large macrocycle L2 is more challenging to afford some interesting dimercury(II) coordination products including a cascade complex. In solution, the dimercury(II) perchlorato complex of L2 as a metalloligand shows a preferential binding of dabco (1,4-diazabicyclo[2,2,2]octane), but its dimercury(II) iodo complex has a much smaller affinity for dabco. In order to explain these results, the solid dimercury(II) complexes with different anions [Hg2(L2)X4] (7: X = I, 8: X = ClO4) were prepared and characterized. Further, the dimercury(II) perchlorato complex 8 reacts with dabco to forms a cascade complex [Hg2(L2)(µ-dabco)(ClO4)2](ClO4)2·2DMF·2ether (9), exhibiting its formation being metal-driven and coordinated anion-regulated. The observed cascade complexation both in solution and solid states is an example of the adaptive guest binding.

20.
Inorg Chem ; 55(5): 2018-22, 2016 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-26885700

RESUMEN

A comparative study on the formation of guest clusters induced by different shapes (or sizes) of exocyclic binding sites embedded in the bis-macrocyclic host isomers is reported. CuI reacts with two regioisomers of a bis-dithiamacrocycle, o-bis-L (W-shaped binding site) and m-bis-L (U-shaped binding site), to yield one-dimensional coordination polymers {[(µ4-Cu4I4)(o-bis-L)]·2CH3CN}n (1a) and [(µ4-Cu2I2)(m-bis-L)]n (2). In 1a, the o-bis-L ligand isomer is linked by a spacious cubane [Cu4I4] cluster, while the m-bis-L ligand in 2 is linked by a smaller rhomboid [Cu2I2] cluster because of the different exocyclic binding sites. The results observed illustrate the possibility for the metal clusters including [CunIn] (n = 2 or 4) to adopt a controlled formation through the binding site alternation or design. Because of the adaptive cluster formations, the products show different photophysical properties. Additionally, sliding of the one-dimensional chains in 1a was observed upon loss of the lattice solvent molecules in ambient condition.

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